He was made King of Italy after the death of Otto III in 1002, while in Germany Henry II was acclaimed king. At first Arduin was "elected by the Lombards in Pavia and was called ‘caesar’ by all", according to the chronicler Arnulf of Milan.Liber gestorum recentium I.14 He then made the rounds of the kingdom with the Archbishop of Milan publicly at his side. The territorial magnates of Italy professed to favour him but secretly were in favour of Henry, according to Arnulf. His enemies in the church, led by Frederick, Archbishop of Ravenna, sided with the new king of Germany. Henry sent Duke Otto I of Carinthia, whom he set over the March of Verona, to face Arduin, who was successful in a pitched battle at Fabrica.

Henry then invaded Italy with a large force that left Germany in March 1004 and arrived at Trent on 9 April 1004. He met Arduin outside Verona, where Arduin was disappointed by a poor showing from his erstwhile supporters. Henry entered Pavia, ancient capital of Italy, and had himself crowned king on 14 May in San Michele, and then burned the city that had given shelter to Arduin. This had its effect: "all of Italy was horrified by this and likewise extremely...Read More